A two port register file or memory cell includes a write port and a read port. The read port includes a bit line or a data line that carries the data read from the memory cell. In various situations, the data line is kept at a logical high voltage level. In some approaches, a voltage keeper is designed to maintain the logical high voltage level for the data line. A voltage keeper of a local input-output (LIO) of a memory array is called a local voltage keeper to be distinguished from a global voltage keeper in other areas of the memory array. A local voltage keeper that is static has a relatively large channel length, and results in an increased layout area for the LIO having the voltage keeper. A memory design without a local voltage keeper or with a dynamic local voltage keeper, together with a dummy write operation on the write port to the memory cell, disturbs a read operation on the read port.
Like reference symbols in the various drawings indicate like elements.